"GLOUCESTER, Mass. –Pete Libra is frustrated. The 40-year-old cod fisherman sees lots of fish in the ocean, and he wants to catch more. Fishing authorities see fewer, and want him to catch less.

"I'm not a scientist. But I see the fish," said Libra. His is the voice of many of the fishermen in Gloucester, the heart of a once-great fishing industry that powered fledgling America and underwrote New England's economy.

Many fishermen here feel threatened by a sweeping new set of fishing limits imposed this spring by authorities trying to rebuild fish stocks they say are depleted by overfishing and facing pressures that include climate change. Federal fishing regulators have traditionally reacted to falling stocks by putting additional curbs on fishing. But that approach may not work in the face of larger environmental changes such as global warming."